Risk factors for the isolation of Haemophilus influenzae in patients with stable chronic obstructive pulmonary disease

Abstract

<sec><title>INTRODUCTION</title>The risk factors associated with Haemophilus influenzae infection in patients with chronic obstructive pulmonary disease (COPD) outside of an exacerbation process are unknown. The objective of the present study is to analyse these risk factors.</sec><sec><title>METHODS</title>Multicentre, prospective study in 201 patients with moderate-severe COPD included between January 2004 and February 2007 and followed for a median of 84 months (between January 2004 and February 2007 with protocolised collection of clinical, comorbidities, analytical, functional, microbiological and therapeutic data, with a medical visit every 3-6 months. Factors independently associated with H. influenzae isolation during follow-up were calculated using logistic regression.</sec><sec><title>RESULTS</title>A total of 517 valid sputum samples were collected (23.6% positive for H. influenzae). The isolation of H. influenzae was independently associated with the accumulated smoking habit (in pack-years: HR 1.31, 95% CI 1.12-1.42), the number of severe exacerbations in the year prior to inclusion (HR 1.65, 95% CI 1.24-2.18) and the percentage value of forced expiratory volume in one second (HR 0.96, 95% CI 0.93-0.98)</sec><sec><title>CONCLUSION</title>Smoking habit, severe exacerbations and the degree of airflow obstruction are associated with the isolation of H. influenzae in sputum in patients with stable COPD.</sec>.